Method and apparatus for containing well pollutants

ABSTRACT

A WELL INSTALLATION APPARATUS AND METHOD, PARTICULARLY FOR OFFSHORE WELLS, UTILIZING A LARGE COFFER OR CAISSON SURROUNDING THE WELL POINT, SUCH COFFER OR CAISSON INCLUDING A SUBMERGED CAISSON HAVING SECURED TO THE TOP THEREOF AN ANNULAR AXIALLY EXPANSIBLE SUBSTANTIALLY WATER IMPERMEABLE EXTENSION SECURED AT ITS LOWER END TO THE TOP OF THE SUBMERGED CAISSON AND AT ITS TOP TO A FLOATING RING.

Feb. 9; 1971 c. G. RIESTER 3,561,220 y *IMETHOD AND APPARATUS FORCONTAINING WELL POLLUTANTS Filed March 26, 1969 INVENTOR C. 650/965RIESTER United States Patent Olce 3,561,220 METHOD AND APPARATUS FORCONTAINING WELL POLLUTANTS Chester George Riester, 10397 South LakeBlvd., Parma, Ohio 44130 Filed Mar. 26, 1969, Ser. No. 810,733 Int. Cl.E02b 1/00 U.S. Cl. 61-34 11 Claims ABSTRACT F THE DISCLOSURE A wellinstallation apparatus and method, particularly for offshore wells,utilizing a large Colfer or caisson surrounding the well point, suchcoffer or caisson including a submerged caisson having secured to thetop thereof an annular axially expansible substantially waterimpermeable extension secured at its lower end to the top of thesubmerged caisson and at its top to a floating ring.

This invention relates generally as indicated to a method and apparatusfor containing well pollutants and more particularly to a coller orcaisson construction for enclosing offshore wells to prevent the escapeof pollutants such as drilling tailings, mud, brine, oil and the like.This invention represents certain improvements in appplicants copendingapplication filed Mar. l, 1968, Ser. No. 709,704, entitled, Method andApparatus for Containing Well Pollutants.

In the drilling of offshore well installations, the containment ofpollutants such as oil, mud, brine, drilling tailings, etc., can be aserious problem. If the well is drilled in a considerable depth of waterit is diicult to provide a caisson or coffer which will adequatelycontain any pollutants which might result.

It is accordingly a principal object of the present invention to providea coffer or caisson for an offshore Well installation which willadequately contain pollutants resulting from the well regardless of thedepth of water in which the well is completed.

Another principal object is the provision of apparatus for containingoffshore well pollutants which includes a submerged coffer or caisson towhich is secured an annular extension which is axially expansible andsecured at its top to a floating ring.

Still another principal object is the provision of a coffer or caissonof flexible water impermeable material which is anchored to the bottomand supported at its top by a floating ring.

Still another object is the provision of a container for offshore wellpollutants which comprises an axially expansible water impermeableflexible cylindrical structure which may quickly and easily be installedabout an olfshore well point.

A still further object is the provision of a caisson for containing wellpollutants which includes a flexible accordion extension, the lower endof which may readily be submerged and secured in place.

A still further object is the provision of a process for containingolfshore well pollutants which comprises anchoring the lower end of aflexible cylindrical liquid barrier while the upper end is floated aboutthe well point.

Other objects an advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described, the followingdescription and the annexed drawing setting forth in detail a certainillustrative embodiment of the invention, this being indicative,however, of but one of the various ways in which the principles of theinvention may be employed.

3,561,220 Patented Feb. 9, 1971 In said annexed drawing:

FIG. l is a fragmentary schematic illustration of a caisson placed inthe bottom surrounding an offshore well point;

FIG. 2 is a fragmentary horizontal section taken through the top of thecaisson as seen substantially from the line 2-2 of FIG. 1;

FIG. 3 is a view similar to FIG. l illustrating the axial flexiblecaisson extension secured in place;

FIG. 4 is a fragmentary vertical section showing in greater detail theaxial caisson extension;

FIG. 5 is a top plan view of one of the ring segments forming thefloating top or the submerged 'bottom of the axial extension; and

FIG. 6 is an enlarged vertical fragmentary section taken substantiallyon the line 6-6 of FIG. 5.

Referring now first to FIG. l, it will be seen that an anchoring orfooting caisson shown generally at 10 may lbe driven into bottom 11submerged beneath body of water 12. The caisson may be driven throughthe bottom 11 to clay 13 or other suitable solid substructure. Theannular caisson 10 may be formed of corrugated sheet p111ng sectionssuch as seen at 15 and 16 in FIG. 2 with each section being providedwith lateral mating flanges indicated at 17 and 18 secured together byfasteners 19. A seal seen at 20 may be provided between such flanges.

The piling may be driven under water using an annular form 1nconventional manner. The diameter of the annular casing may be selectedbased upon the size and number of'well points to be completed within thecaisson. The calsson may be several hundred feet in diameter, forexample.

Secured to the interior of the footing caisson is an adaptor ring 22 andthe corrugations of the piling may be provided with a suitable sealantseen at 23 so that the caisson is connected to the adaptor ring in anessentially watertight manner.

As seen perhaps more clearly in FIG. 4, the upper interior portion ofthe adaptor ring 22 is provided with a plurality of downwardly andinwardly projecting locking fingers 25. Such fingers cooperate withapertures 26 in anchoring ring 27, the details of which are seen moreclearly in FIGS. 5 and 6. Such anchoring rings may be comprised of aplurality of interconnected arcuate sections, one end of each sectionbeing provided with a tongue seen at 28 while the opposite end isprovided with groove or slot 29.

The anchoring ring sections may be constructed of a reinforcedrubberized fabric material and include an arcuate vertically elongatedchamber 30, the interior wall of which is connected through web 31 tovertically extending interior ring 32. The apertures 26 are providednear the lower edge of the ring 32 on the same peripheral or arcuatespacing as the lingers 25. The top of the ring 32 is also provided witha series of similarly spaced and shaped apertures as seen at 34. Thechamber 30 of each ring sector is provided with valves seen at 35 sothat either air or liquid may be admitted into such chamber.

The top of the adaptor ring 22 its into the downwardly facing slot 36between the interior wall of the chamber and the lower portion of theinterior ring 32. The `fingers 25, of course, ft within the apertures 26securing the anchor ring 27 to the top of the adaptor ring 22.

The anchor ring 27 is also secured in similar manner to flexible caissonextension 37. The lower cylindrical axial portion 39 of the extension 37lits within the annular slot y40, seen in FIG. 6. The axial lowercylindrical end 39 is provided with inwardly and upwardly directedlingers 41 which lit within the apertures 34 thus securing the lower end39 of the extension 37 to the anchor ring 27.

The extension 37 comprises for its major part an accordion pleatedflexible rubberized fabric so that it can collapse into a relativelysmall vertical package. A vulcanized rubber fabric having reinforcingcords of nylon, polyester or rayon, for example, can be employed tofabricate the extension.

The top of the extension has an annular axial cylindrical portion 43which may be of the same dimension and configuration as the bottomcylindrical portion 39. The top cylindrical portion 43 is provided withdownwardly and inwardly directed fingers 44 which lock into apertures inthe inner ring 45 of top ring 46. The top ring 46 may be identical inform to the anchoring ring 27 and is provided with an annular exteriorchamber 48 secured to the inner ring 45 by central web 49. The charnber48 is provided with valves 50 for infiation of the chamber or fillingthe same with liquid.

An upper extension, not shown, may be provided by mounting a ring in theupwardly opening slot 51. This may serve to prevent pollutants fromsplashing over exteriorly of the containing caisson. In manyapplications, however, a further extension of the caisson may not berequired.

`In installation, the rings 46 and 27 are secured to the ends of theextensible extension 37 with the fingers 44 and 41 placed within theapertures in the internal rings 45 and 32, respectively. The chambers 48and 30 may now be inflated and this causes the interior chamber wall tobear against the axial cylindrical end portions of the extension 37tightly confining such end portions in the slot and, of course, thefingers in the apertures. This locks the ring to the extension andprovides a substantially Iwater impermeable seal therebetween.

After the submerged foundation caisson 10 has been placed with theadaptor ring 22 thereon, the caisson extension is oated to a positionabove the caisson. The lower or anchor ring 27 may now be filled withwater or ballast and the lower end of the extension dropped to fit ontothe adaptor ring 22. As the lower ring drops, the extension axiallyexpands. The locking fingers 25 are positioned within the apertures 26and the chamber 30 may then be pressurized to provide a securesubstantially watertight connection between the caisson extension 37 andthe anchor caisson 10.

The axial cylindrical extensions 39 and 43 may be made of neoprene orrubber of a thickness greater than that of the pleated portion of therubberized fabric therebetween. The locking fingers may be molded intosuch end portions and cotter pins connected together by a chain may beemployed to ensure against disassembly. The top floating ring `46 may beanchored to the drilling platform inside the caisson to ensure againstlateral drift.

In some installations it may be possible to omit the anchoring orfooting caisson 10. In this case the bottom ring 27, suitably weightedor anchored, would simply rest on bottomi 11, its flexibility permittingsubstantial conformance thereto.

It can now be seen that there is provided an easily installed simplifiedcaisson which includes a pliable, rubber fabric with floating orsubmersible collars which may readily be anchored to a submerged caissonto form a complete containment about an offshore well site. If oil orother contaminants spill into the water at the well site, they can bepumped or clam-shelled from within the caisson into a barge or likevessel alongside the caisson. The hydrostatic pressure balance canreadily be maintained by pumping sea water into the inteiror of thecaisson.

I, therefore, particularly point out and distinctly claim as myinvention:

1. Apparatus for containing offshore well pollutants comprising anannular submerged caisson surrounding an offshore well point, and anannular extension of said caisson comprising an annular axiallyexpansible water impermeable member secured at its lower end to the topof said caisson and extending to the waterline to form a liquid barriersurrounding such well point.

2. Apparatus as set forth in claim 1 including a fioating ring to whichthe top of said extension is secured.

3. Apparatus as set forth in claim 2 wherein said oating ring includesan inner vertical wall and an outer chamber, the top of said extensionbeing positioned between said wall and chamber, and means to pressurizesaid chamber to squeeze the top of said extension between said chamberand wall.

4. Apparatus as set forth in claim 3 wherein said wall is provided witha, plurality of apertures, and locking `fingers on the top of saidextension extending through such apertures.

5. Apparatus as set forth in claim 2 including a ring identical to saidfloating ring securing the lower end of said extension to said annularsubmerged caisson.

6. Apparatus as set forth in claim f1 wherein said annular extensioncomprises an accordion pleated rubberized fabric.

7. A method of containing offshore Well pollutants comprising the stepsof forming an annular submerged caisson surrounding an offshore wellpoint, oating a caisson extension into position over said caisson,axially downwardly extending such caisson extension and securing thelower end thereof to such caisson while maintaining the upper endthereof floating.

`8. Apparatus for containing offshore well pollutants comprising acylinder which is axially collapsible and extensible, rings at the topand bottom of said cylinder, and chambers in said rings whereby thebuoyancy of the top and bottom of said cylinder can be controlled.

9. Apparatus as set forth in claim 8 wherein the major extent of saidcylinder is a flexible fabric having accordion pleats therein.

10. Apparatus as set forth in claim 8 wherein said rings include aplurality of interconnected individual sections each including achamber, and valve means for admitting uid to said chambers.

11. Apparatus as set forth in claim 8 wherein each ring is connected tothe ends of said cylinder by a locking connection, the pressure in saidchambers maintaining said connection and enhancing the water sealtherebetween.

No references cited.

PETER M. CAUN, Primary Examiner

